1. Technical Field
The present invention relates to a virtual image display apparatus including a head mounted display that presents images formed by an image display device or the like to an observer.
2. Related Art
Various systems have been proposed as optical systems incorporated in virtual image display apparatuses including head mounted displays (hereinafter, also referred to as HMDs) attached to heads of observers. Of them, for example, for preventing generation of ghost light due to image lights, systems with characteristics in layer or film parts for adjustment and control of lights such as a system having a bonding layer for bonding a part in which a half mirror of optical components is formed contains a dye (see Patent Document 1 (JP-A-2012-168425)) and a system having a half mirror that reduces variations in reflectance with respect to incident angles of lights (see Patent Document 2 (JP-A-2010-230771)) are known.
Here, in an HMD or the like as the above described virtual image display apparatus, formation of high-quality images with high contrast, i.e., sufficiently dark in black representation parts is required as is the case of image projection by a projector or the like. For example, in a see-through HMD that allows visual recognition in superimposition of outside world light and picture light, no image is displayed in the black representation parts and the outside world is seen through. The higher the contrast (the darker the black), the clearer the field of view of the parts not displaying images, and accordingly, higher contrast is particularly desired for the panel.
In order to obtain the higher contrast of the panel, e.g. image formation by a self-emitting display device such as an OLED is considered. However, in the case of using the OLED or the like, there are problems in higher brightness and longer life. For example, if priority is given to the longer life, it may be possible that e.g. color balance (luminance balance between lights in different wavelength ranges) deviates. It is hard to use image lights with the deviated color balance and adjustment and control of lights may be required.